This work-package is leaded by Vincent Rossi (MIO, junior CNRS researcher)

Our aim is to fully characterize the mean patterns and magnitude of larval connectivity among SEAMoBB sites (“basin-scale”) and within the bay of Marseille (“regional-scale”) for several benthic species based on bio-physical modelling. Our objectives are (1) to provide general information about larval dispersal (predicted by our model) among the eight SEAMoBB sites and (2) to compute specific connectivity proxies for Marseille region and for each sampled site within the bay of Marseille, as well as pair-wise probabilities of connection. This information will feed in the statistical analyses to potentially explain the observed biodiversity patterns and colonization rates. In an analogous way, the pattern and magnitude of larval connectivity along the coast of Spain and/or Italy could be characterized if additional funding could allow extending our analyses. To do so, we will apply the Lagrangian Flow Networks (off-line Lagrangian model) to assess marine connectivity across the Mediterranean and within the bay of Marseille for a range of representative benthic species. As input, we will use multi-year outputs (2-dimensional or 3-dimensional gridded velocity field) generated by high-resolution state-of-the-art ocean circulation models developed at both basin- and regional-scales. We will incorporate the impacts of heterogeneous habitats (produced by WP2) within our numerical experiments. Following a statistical approach, we will generate a large number of connectivity matrices obtained with realistic biological traits and covering all possible circulation schemes to deduce robust connectivity estimates. Concrete outputs will consist in mapping and statistically analyzing various simulated connectivity proxies and their spatio-temporal variability.